Cope. ] 488 [Sept. 19, 1872. 
longation of the muzzle. In front of the zygomatic arches, the form is 
compressed and roof-like above. Above the tusks the nasals expand, and 
are produced to a great distance, terminating in osseous prominences., 
The premaxillaries are also much produced ; their anterior part is slender 
and toothless, and does not extend so far as the nasals. 
The orbit is not inclosed behind, and has no marked superciliary or 
other margin. Above it, on each side, a horn-core is given off, the pair 
diverging from approximated bases. Occiput vertical. 
The affinities of this genus are not close to any known, excepting Bath- 
modon. This has the six premaxillaries of nsual proportions, at least 
three true molars, and the posterior premolars with three crescents. The 
general relationships are proboscidian, and associated in some measure 
with Synoplotherium, Auchippodus and Pseudotomus. 
Besides the L. semicinctus, Cope, originally described, the researches 
under Prof. Hayden’s Geological Survey, have determined the existence 
of two or three other species of much larger size. 
LOXOLOPHODON CORNUTUS. Cope. 
Hobasilus cornutus. Cope. 
Established on portions of several skeletons, including one with femur, 
pelvis, scapula, vertebrae and cranium, The latter measures about thirty- 
four inches in length. The horn-cores are very stout and sub-triangular 
in section at base and with a rudimental knob on the inner side ; height 
seven inclies about. A massive protuberance of a recurved lobate 
outline rises on the anterior margins of the nasal bones on each 
side. They meet, leaving an emargination in front, giving the nasal 
bones a bi-lobed outline. The iliac bones are very wide, the expanse of 
both together being fifty-four inches. The centrum of a sacral vertebra 
is four inches in diameter. 
LoxoLOPHODON FURCATUS. Cope. 
This species is indicated by portions of the nasal bones. These have 
differed in form materially from those of the L. cornutus. The convex 
protuberances seen in L. cornutus were here represented by processes of 
singular form. They were compressed, narrowed at the base, and 
expanded distally into a flat spatulate body. The whole process measures 
seven to eight inches in length, and three and a-half in width distally. 
The animal could not have been materially smaller than the L. cornutus. 
LOXOLOPHODON PRESSICORNIS. Cope. 
Established on numerous remains, including horn-cores of species sim- 
ilar in size to the last. Its marked peculiarity, as first noticed, consists 
in the compression of the horn-cores throughout the proximal half of 
their length, with their more acuminate form, than in L. cornutus. They 
measure also about seven inches in length. 
The affinities of these remarkable animals will be shortly discussed. 
They were the gigantic mammals of our Eocene period, representing 
the Elephants and Mastodons of the Miocene, which they equalled in 
size. 
